A gas turbine engine (“GTE”) is known to include a turbine assembly having one or more turbine rotor assemblies mounted on a drive shaft. Each turbine rotor assembly includes a plurality of turbine blades extending radially outward and spaced circumferentially from one another around a turbine rotor. The GTE ignites a mixture of air and fuel to create a flow of high-temperature compressed gas over the turbine blades, which causes the turbine blades to rotate the turbine rotor assembly. Rotational energy from each turbine rotor assembly may be transferred to the drive shaft to power a load, for example, a generator, a compressor, or a pump.
A turbine blade typically includes a root structure and an airfoil extending from opposite sides of a turbine blade platform. The turbine rotor includes a slot for receiving the root structure of each turbine blade. The shape of each slot may be similar in shape to the root structure of each turbine blade. When a plurality of turbine blades are assembled on the turbine rotor, an under-platform cavity may be formed between and beneath turbine platforms of adjacent turbine blades.
Components positioned within the under-platform cavity for regulating the flow of compressed gas around turbine rotor assemblies are known. One example of such a component is described in U.S. Pat. No. 7,097,429 to Athans et al. (“the '429 patent”). The '429 patent discloses a rotor disk including a plurality of turbine blades. Each turbine blade includes an airfoil, a platform, and a shank. The shank may extend down to a multi-lobe dovetail to mount the turbine blade to the rotor disk. A seal body is positioned between the shanks and below the platforms of adjacent turbine blades. The seal body includes an enlarged seal plate disposed at a forward end of the seal body. The enlarged plate overlaps portions of forward faces of adjacent turbine blade shanks to provide a seal. The seal body also includes an aft end with a generally rectangular head disposed above a pair of axial lobes. The aft end head has an area that is smaller than the seal plate at the forward end.